I've had GSam on my S5 for a while (SM-G900T1, 4.4.2 rooted) along with the GSam Root Companion. The last time I used it (don't recall how long ago that was but not that recently) it worked fine. I just tried to use it today and it briefly opens to a blank screen than FC's. I tried the usual things, uninstall/reinstall, clearing cache and data as well as reverting to older versions that I know had worked. Still the same thing. I haven't made any significant changes to the phone that would cause this so I'm at a loss for the reason it's happening.